In Super Mario Galaxy you fight Bowser three times throughout the game. It can be a very crucial moment, so here are some tips so you can be ready when the time to square off against the Koopa King comes. He's actually not all that challenging if you know how to play the game though.

Steps

1

Jump into the air to avoid the shock waves when Bowser performs his stomping move. If several shock waves occur (especially in the last battle), you won't have time to land between each wave, so the use of Mario's spin move in the air can help you stay airborne a bit longer. (Stay at the planet's circular pole; it will help you avoid the shock waves better because they will be more scattered.)

2

Hit him in the opening of the rock where his face is showing if Bowser collects rock around him and rolls towards you. You require some good timing and a bit of luck. Try to predict when the opening comes around again and time your spin attack accordingly.

3

Run when Bowser shoots fireballs. There is no real strategy for this, just run around and try your best not to get hit.

4

Spin through the bouncy plants after the fireball attack for them to hit Bowser, which can be quite tricky. Be sure not to hit yourself when they come back.

5

Avoid Bowser when he forms into a spiky ball and spin towards you. He'll do this in a circular pattern; you can't attack him at this point, so just avoid him.

6

Hit him when he jumps up into the air. Since he always falls in your direction (and if you're close enough, he lands where you were when he began his jump). Stand over the blue spot filled with lava. When he lunges toward you, run off the blue spot. If done correctly, he will land there, shattering the blue glass and his tail will combust. As he frantically runs around, run in the opposite direction and meet with him halfway around the planet. He will attempt to turn and run away again, but before he can spin and hit his tail. He will then flip over and possibly spin on his shell. You may need to hit him numerous times while he rolls depending on what battle it is. He can get rolling pretty fast so be sure not to get flattened! If you wait too long, the fire on his tail dies away and he begins attacking again.